Water-cooling system for outboard motors



Dec. 30, 1930 I o. EVINRUD. 1,786,835

WATER COOLING SYSTEMFOR 0T BOARD`MTORS Filed Oct. .20. 1928 2 Sheets-Sheet l -oooooooobc ooooooooo o aaacnooovaa vi INVENTOR. ULE E mm1/0E MMM/M ATTORNEYS.

Dec. 30, 1930. l o. EVINRUDE WATER COOLING SYSTEM FOR OUTBOARDJKITORS 2 Sheets-Sheet Filed Oct. 20. 192B L Y I ATTORNEYS.

l atented Dec. 30 1930 arr-ao STATES' PATNT orric OLE EVINBI'UDE, 'DTF MILWAUKEE, WISCONSIN, SSIGNGR, BY MESNE'ASSIGNMENTS, T0 @UTIBOABD MOTORS CGBPOEATION, A. CORPORATION OF MICHIGAN v l WATEB-GOGLING SYSTEM FOB y0`l".l`.BQ.AItID MOTORS Application led ctober 20, 1928. Serial No. 318,737.

This invention relates in general to out board motors and more particularly to a water cooling system` especially designed and Vadapted for organizationy with such motors.

The problem of cooling an outboard motor is a long standing one in this art and in an effort to solve it various expediente have been resorted'to. For instance, it has been proposed to drive plunger pumps from the mo l tor but this expedient has not provensatisact'or for a number of reasons. ln the i ir'st p ace the pump of the plunger type lacks the` capacity to satisfactorily serve the requirements o an outboard motor when the pump is built of a size. appropriate to the general design and plan of construction of such a motor. Further, it is dicult to construct a plunger pump that will stand up under the usage met in outboard motors. The plungerl must be a uid tight fit in its barrel and this cannot be' maintained as both plunger and barrel become badly scored in use due to the presence of sand and the like in the Y Water being handled. YAnother expedient that has been resorted to is the organization of apropeller pump with motors of this type. Propeller pumps are not as positive as are' necessary. In an outboard motor the water cooling system necessari-ly utilizes very small pipes and corrosion and obstructions resulting from the presence of'sand, mudfleaves, grass, etc., in the Water willreduce the volume of flow of the cooling medium or prevent it whenthe propeller is relied upon to impel the water through the system. Further, any variation in the propeller speeds eiects a correspond- .ing variation in the flow of the propelling medium and a great reduction in such ow, 40 occurs when the motor is slowed down.

One of the principal objects" of the presentinvention resides in the provision of a water cooling system for an outboard motor of such a character as to be susceptible of convenient incorporation into the construction of the motor and as to be capable of developing amplel and adequate flow of vthe cooling medium through the systeml under all circumstances. The circulation of the Water throu h the cooling system is entirely posit-ive an at all engine speeds the Water is circulated in suiiicient volume to satisfy the requirements of t-he motor and prevent dangerous and invjurious overheating. To prevent the development of excessive pressures in the water cooling system the present invention proposes for the automatic relief of the pressure When it exceeds a predetermined amount.

Another object of the invention is to provide a water cooling system of this character having a pump so constituted that its e`e0 tiveness lWill'not be impaired by the action of Sand, grit, or the like.

A further object of the invention resides in the provision ont a pump of this character which does not appreciably or materially cut down the power output of the motor although utilizing the motor as the source of its positive actuation. l

Another object of theinvention resides in the provision of a Water. cooling system which not only cools the cylinders of the motor but which also prevents excessive overheating of the mumer.

Another object of the invention is to provide an outboard motor having a water coolling system of the character mentioned incorporated in the structure in such manner that the pump and other elements of the water cooling system are, for the most part, entirely housed and protected' and yet are readily accessible for purposes of adjustment, replacement or repair; should such become necessary. l

Still another object of the invention resides in the provision of awater -coling system of an outboard motor which -is simple and durable ingconstruction, reliable and ef- :Eective in operation and easy and comparatively ineX ensive to manuifacture. I

Other o jects and Nadvantages reside in certain novel features of the construction, arrangement and combination of` parts, which will be hereinafter more fully described and particularly pointed out in the appended claims, reference being; had to the accompa-nying drawings forming a part of this specification, and in which: Figure 1 is a view partly in rear, elevation and partly in section and"illustratngan outboard motor equipped with al water pooling system embodying the present invention;

Figure 2 1s al fragmentary view 1n ele- 'vation of part of the motor shown in Figure 1, the muiller being removed andparts being shownin section for the sake of illustration;

Figure 3 is a view partly in central vertical longitudinal section and partly in side elevation further illustrating the water cooling lsystem of the motor shown in Figure 1;

Figures 4, 5 and 6 are views in horizontal section taken on lines 4 4, 5-5 and 6 6, respectively, of Figure 3; and

Figure 7 is a fragmentary view in front elevation showing the construction of the lower portion of the motor and illustrating the inlet to the pump thereof.`

Referring to the drawings wherein for the sake of illustration is shown one embodiment of the invention, the numeral l designates generally an outb'oard'motor which has its cylinders 2 provided with water jackets 3. The cylinders of which four are shown are secured to the opposite sides of a crank case 4 in accordance with the standard practice. The crank shaft of the engine is not shown but in the type of motor illustrated it is constructed, mounted and driven as illustrated in the co-pending application of Gle Evinrude `for four cylinder outboard motors, filed February 27, 1928, Serial Number 257,501, to which application reference is made for a full disclosure of these features.

For the purposes of the present invention, it is suficient to understand that the engine has its crank shaft coupled to a drive shaft 10 which extends downwardly through a sec-A tional housing designated generally at 11,

the drive shaft 10 being geared to a propeller shaft 12 by intermeshing beveled gears 13 and 13. The rearward endV of the propeller shaft 12 projects exteriorly of the housing and has a propeller 14 mounted thereon and suitably connected thereto.

The housing 11 includes an upper tubular section 15 having a bearing sleeve portion -16 adapted to be rotatably fitted in a bearing bracket clamped or Otherwise secured to the stern of the boat in accordance with the usual practice. The sectional housing 11 is completed by a lower housing section 17 of the approximate stream-line section shown in the drawings and the two sections are held in assembly by stud bolts 18 threaded into the flanged upper end 19a of the lower housing section 417 and extending through an o`ut-` wardly directed annular flange 19 formed at the lower end of the upper housing section 15,

nuts 2O being threaded o n the stud bolts and bearing against the flange to secure the parts assembled. Any suitable fastening device may be employed in lieu of the stud bolts 18 and nuts 20. A gasket or other suitable packing may be provided between the sections of the housing. l

A centrifugal pump is incorporated in the housing 11 and the chamber 24 of this pump is defined by coacting structure of the housing sections. Thus, as shown in Figures 3 and 6 the upper section 11 has a transverse wall 25 adjacent its lower end. The transverse wall, although set up within the lower end of the housing section 15 slightly, completely closes the lower end of the upper housing section 15 proper, except for a flanged central opening 26 provided in the wall and through which the drive shaft 10 loosely extends. The structure of the pump chamber also includes a transverse or horizontal wall 28 integral with the lower housing section and just slightly spaced from the upper end of the lower section.

The upper housing section 15 has an 1ntegral downwardly directed rib or flange 21 which interfits with the lower section in the assembly for the purpose of alining the sections and also ior defining the contour of the periphery of the pump chamber. As clearly shown in Figure 6, the flange 21 extends spirally about the axis of the shaft 10 and extends from one side of the outlet from the pump chamber to a point slightly spaced from the opposite side of such outlet. The flange 19 is of gradually increasing or tapering thickness from one end to the other.

The lower housing section is formed with the inlet to the pump chamber and preferably this inletis defined by means of a wall 30 cast' integral with the wallv 28, with the lower section 17 of the housing'and with a bearing sleeve 31 through which the drive shaft 10 extends. The inlet passage thus de-i fined is designated at 32 and communicates with the pump chamber 24 Athrough an opening 34 provided at the center of the wall 28. At its lower end the inlet passage 32 has a screen intake opening 33 positioned in the forward portion of the lower section of the housing whereby the inlet passage acts as a scoop to feed the water to the pump chamber and to aid in the circulation of the water through the system when the boat is running ahead. Asshown, the wall 30 extends between opposedy walls of the lower housing section 17 and Iinwardly and upwardly from the intake opening 33 until it merges into-the sleeve 3l and above the sleeve 31 the wall is offset inwardly with respect to the lower portion thereof and to the sleeve 31 as indicated at 31 so that theinlet passage 32 has free and unobstructed communication with the impeller are a number of blades or vanes 43' which curve outwardly from the hub and rearwardly with respect to the direction of rotation of the impeller. As shown in Figure 6, the impeller, although mounted on the drive shaft and thus concentric with the housing proper, is somewhat eccentric with respect to the inner peripheral wall of the pump chamber 24 since this wall of the pump chamber is defined by the flangel 21 which is eccentric or spirally curved with respect to the axis of the shaft l0.

The pump chamber communicates at one point inits periphery with a discharge passage 45 formed in a rearward enlargement or extention l5a integral with the upper sectionV l5 ofthe housing 11. f

The impeller vanes 43 wipe against the peripheral wall of the pump chamber for a small portion only of its angular extent, as

-will be understood from Figure 6. Past the zone of contact of thevanes 43 and the peripheral wall of the pump chamber, the peripheral wallv curves gradually away from the path of the blades to provide a space enlarging toward the outlet and into which'the impeller throws the water.

The discharge passage is connected by means of a coupling 47 with a pipe 48 having branches 49 'leading into the water jackets 3 of the cylinder. Afterk circulating through l ce the water jackets 3, the water passes through short pipes 50 to thewater `spaces or water jackets 5l formedin the heads 52 of the mufiier designated generally at 53. Thus, the water, after cooling the'cylinders of the-engine, further cools the heads of the muiliers and tends to prevent the muliiers from becomingltoo highly heated. In addition to their water jackets, the mulers are formed with fins also operating to radiate and dissipate the heat.

. With this construction, when theengine is running and when the lower end of the housingy is submerged in the water as it always is when the motor is in operative position on the boat` the impeller 40 partakes of the rotation of the drive shaft 10 and forcesthe water from the pump, chamber into the dis'- charge passage with a centrifugal action and consequently also draws water into the pump chamber through the inlet passage 32. The .water passes into the spaces between the vanes 43 adjacent the hub 41 and is-thrown outwardly by the rotating vanes andY around to they outlet 45. WhenA the boat is moving forwardly the feed of the water to the pump chamber resultsnotl only from the ac'tcnjof the impeller but also from -the scoop-like action of the inlet 33 which picks up the water as the boat advances and displaces it up through the inlet passage 32 into the pump chamber.,

' As the speedof the motor and boat increases the force with which the scoop inlet feeds the water to the pump chamber correspondingly increases and' the inrushing water acts on the vanes 43 in a manner tending to rotate the impeller and drive shaft thereby compensating for any fraction of the powerv out-put of the motor that would otherwise be required to drive 'the pump. With .al-,comparatively small size impeller a high degree of pressure is developed and a very efficient pumping action is had so that the water will be positively circulated and the system will be maintained clear of obstructions that, in the absence of positive circulation, might build up in the system as a result of corrosion or as aresult of the deposit in the system of some of the suspended matter in the water. .And sand, grit, or the like, even if it scores the vanes of the 1m peller or the walls of the pump chamber,

will not impair the eiiiciency of the pump inasmuch as the vanes -will remain effective to throw the water outwardly and around toward the outlet. While it is desirable to have the vanes havel wiping contact with the peripheral wall of the pump chamber 'ust past the outlet, this Contact need not e so liquid tight as the plunger inthe barrel of a reciprocating pump. In fact, the

lou

pump disclosed is so eiiicient and'` develops j such a positive circulation that there may be some possibility of excessive pressures developing in the system at times and to prevent the pressure from building up above the-desirable and proper amount the discharge lpassage may, if desired, be provided with a vent or relief port 60 normally closed by a safety valve 62 which may consist of a disc 63 carried by a blade sprlng 64 of proper strength, one end of the blade spring being fixed to the disc"valve and the other end being fixed by means of a screw 66 to a seat 65 provided on the upper housing section 11. yThe strength of the spring 1s such defines the inlet passa e also delines a gear housing or gear cham er-7O which is completely enclosed and which houses and rotects the beveled gearing and the bearings for the propeller shaft as well as the lower bearing for the drive shaft. To permit of as to maintain the safety valve closed until convenient assembly of these parts, the

13 and the roller bearing assemblies R and R for the propeller shaft are mounted on the propeller shaft. I n the assembly the inner bearing R for the propeller shaft is received in a flanged bearing seat 78 formedv in the housing. The flange 78 of this seat limits the inward movement of the inner propeller and, of course, the outward movemay operate' in pump chambers of the appended claims.

ment of this bearing assembly and of the other elements on the propeller shaft is prevented by the action of the combined lcarrier and closure 76 and the stud bolts 77.

The portion of the drive shaft l0 just above the sleeve gearing 3l and lying in the path of the incoming Water may be protected by a bushing 90. AIf desirable, suitable packing may be employed between the sleeve 30 and the shaft 10. At the lower end of the sleeve 30 a roller bearing -B is provided for the shaft 10. The lower section of the housing may have a cavitation plate C integral therewith. 4

The pump chamber may be built in the housing well above the water line and so may be made of any size without increasing the resistance to the forward motion of the boat. Further, the impeller is driven from the drive shaft and at drive shaft speed, a

very desirable feature over a propeller shaft drive inasmuch as the propeller shaft is usually geared down. The character of the inlet is one of the features that makes this nrvel and advantageous organization pos,- si le.

Obviously, various changes 'in the size, shape and arrangement -of parts may be made Without departing from the spirit and substance of the invention and the scope of In particular the shape of the vanes and the construction and form of the pump chamber may be varied. Thus straight radial vanes, in lieu of curved vanes, may be employed and the impeller various shapes. The invention claimed is: l. In combi-nation with an outboard motor having jacketed cylinders, a drive shaft actu- `ated from the motor, a propeller shaft geared to the drive shaft and having a propeller fixed thereto, a housing for thc drive and propeller shafts and the gearing, said housing including sections having coacting means defining a pump chamber, an impeller in said chamber actuated from the drive shaft, the lower section of the housing having an inlet to the pump chamber opening forwardly at a point adjacent the propeller shaft whereby to be well submerged, the other section having an outlet leadingltherefrom, and means connecting the pump outlet with the jackets of the cylinder.

2. In combination, an outboard motor having a. water cooling system, a propeller, driving means for the propeller actuated from the motor, a housing for the driving means including sections having coacting structure defining a. pump chamber, an impeller operating in vsaid pump and actuated from the driving means, one of the sections of the housing having aninlet passage leading into the pump chamber, the other section of the housing having a discharge passage communicating with the pumpv chamber and connected'to the water cooling system, said discharge passage having a reliefport and a safety valve y coacting with the relief port.

3. In' combination, an outboard motor having a water 'cooling system, a propeller, driving means for the propeller actuated by the motor. a housing for the d'riving means, a centrifugal pump in said housing and actuated froin the driving means, a connection between the pump and the water cooling systeni, and means for automatically relieving the system of the cooling medium when the pressure exceeds a predetermined point.

4. In combination, an outboard motor having a water cooling system, a propeller, driving means for the propeller, a vhousingI for the driving means made up of a pair of sections having coacting structure defining a pump chamber, an'impeller operating in the pump chamber and actuated from the driving means, the lower section of a housing having an 'intake opening and having an internal Wall defining an inlet passage leading from the intake opening to the pump chamber and also defining a separate gear chamber for elements in the driving means, and a connection between the discharge of the pump and the water cooling system.

5. In combination, an outboard motor having a water cooling system, a drive shaft actuated from the motor, a propeller gearedA to the drive shaft, 'a housing for the drive shaft, said housing having spaced transverse Walls definin a pump chamber, said walls having openings through which the drive shaft loosely passes, the peripheral wall of the chamber being eccentrically or spirally curved, an impeller operating the said pump chamber and including a hub fixed to said drive shaft, a plate-like body fixedly connected tothe hub and bearing against one wall to close the opening thereof, and vanes fixed to rotate with the hub and body and located on one side of the body, the housing having an inlet communicating with the unobstructed opening of the pump chamber, and discharge means communicating with a peripheral porn tion ofthe pump chamber, the vanes having wiping contact with the-peripheral wall for a portion of its angular extent.

6. In combination, an outboard motor having a water cooling system, a drive shaft actuated from the motor, a propeller geared to the drive shaft, a housing for the drive shaft, said housing having spaced transverse Walls delining a pump chamber, said walls having openings through' which the drive shaft loosely passes, Can impeller operating in said pump chamber and including a `hub fixed to said drive shaft, a plate-like body ixedly connected tothe hub and bearing-againstone wall to close the opening thereof, and vanes fixed to rotate with the hub and body'and located on one side ofthe body, the housing having an inlet communicating with the unobstructed opening of the pump chamber,

and discharge means communicating with a peripheral portion ofthe pump chamber.

7. In combination, an outboard motor, a water cooling system therefor, a drive shaft actuated from the motor, a propeller shaft,

a propeller fixed to the propeller shaft, intermeshing gears, one on each of said shafts, bearing assemblies mounted on the propeller shaft, a supporting and enclosing housing for "the said shafts and gearing having an'opening permitting ofthe assembly of the" pro# peller shaft and of the elements carried thereby as a unit, and a closure mounted .on the propeller shaft and adapted to be interfitted with the opening and secured to the housing to maintain the assembly, a pump actuated from the ldrive shaft located in said housing and connected with the'water cooling system, and means within the housing-defining an in` let to said pump anda separate gear chamber for the propeller shaft gears and bearings. i

8. In an outboard motor having an engine, a propeller and an upright drive shaft operatively connected with said engine and said propeller, of a shaft housing of substantially stream lined contour in horizontal cross seotion in its submersible portion, the shaft being disposed in the widest part of said housing and the walls of said housing being extended convergingly at the rear of the shaft,

' of a Water circulation s stem including a pump chamber in the wi er portion of said housing atan intermediate point therein, a water passage formed in said housing below said chamber and ,leading centrally. thereto from an inlet disposed materially therebeneath,'and a delivery passage formed above said chamber -between the rearwardly converging walls of said housing, together with a centrifugal pump runnermounted on said shaftfwithin sai-d chamber.

9. In an outboard motor structure, a lower unit comprising ar sectional shat hbusing having j an anticavitation plateA adjacent which the shaft housing sectionsv are-secured together, the abutting ends of said sections being formed to provide a'pump chamber constituting an enlargement of said plate, a

pump in said chamber operatively connected for operation fromsaid drivev shaft, an inlet passage leading to said chamber from below said plate, and a delivery passage leading upwardly from said chamber above said plate. A

10. In an outboard motor, a lower unit com prisingan upright drive shaft and a housing therefor of approximately stream lined contours in horizontal section, the submersible portion of said housing being-provided with an anti-cavitation plate centrally thickened in a vertical direction and having internally unit comprising an upright drive shaft lcarrying a pump' runner intermediate its ends', a housing enclosing said shaft, a'partition within said housing terminating below said runner and providing a water passage having an opening to the exterior of said housing and leading centrally to said runner, said partition being formed to enclose said shaft to a point adjacent said runner, a bushing extension of said partition encircling said shaft and embodying the lower facefef said runner, and partitionmeans above saidrunner delining a deliverypassage spaced wholly at one side of said shaft for the delivery of water upwardly from said runner, whereby water and `grit are excluded from contacting said shaft.

12. In an outboard motor, the combination with a 'drive shaft `and cylinders respectively disposed at o posite sides of said drive shaft j v are adj acent.

13. In an outboard lmotor` structure, the combination with: a drive shaft and cylinders disposed at opposite sides thereof, of a muiier mounted approximately parallel to the cylinders and provided with heads operatively connected to receive exhaust gases from respective cylinders, a muiiier structure provided with an exhaust outlet disposed be- 11. In an outboard motor structure, a lower I iso tween said heads, independent jackets for said heads, and a cooling system for said engine including connections toY the jackets of the muler heads. j

14. In an outboard motor structure, the combination with a plurality of cylinders, of a muler having its ends connected with different cylinders and provided with an outlet for exhaust gases from the cylinders to which the ends of the mufller are connected, indev pendent water jackets on the ends of said muler, and a Water supply passage branched to provide individual connections to the ree spective jackets.

15. In an outboard motor structure, the combination with a plurality of cylinders, of a muller having its ends connected with different cylinders and provided with an outlet for exhaust gas from the cylinders to which the ends of the muiler are connected, independent Water jackets on the ends of said muler, and a water supply passage branched to provide individual connections to the respective jackets, said cylinders being rovided with jackets .respectively communicating with the jackets on the muer portions receiving exhaust gases therefrom.

In Witness whereof, I hereto aix my signature.

OLE EVINRUDE. 

